The present invention relates to golf balls having at least one layer formed from compositions including at least one of a polyamide, in the form of a homopolymer, a copolymer or mixtures thereof, or an olefinic polymer produced using a single-site metallocene catalyst in the polymerization process, to which at least one pendant functional group has been grafted by a post-polymerization reaction. The polyamide compositions may be mixed with ionomers or non-ionomers, including grafted or non-grafted metallocene catalyzed polymers. The grafted metallocene catalyzed polymer compositions may be mixed with at least one of an ionomer, a non-grafted or unfunctionalized metallocene catalyzed polymer, polyamide, or other non-ionomeric polymer to form a blend. The compositions may be used in any layer of a golf ball, may be foamed or unfoamed, and may include at least one density-adjusting filler.
Golf ball manufacturers are constantly attempting to construct golf balls having a desirable combination of good xe2x80x9cfeel,xe2x80x9d distance, and durability. One way in which the properties of a golf ball may be adjusted is through the cover composition and construction of the ball. Traditionally, softer feeling golf balls were obtained by providing an outer cover formed with natural or synthetic balata over a liquid center surrounded by a tensioned elastomeric wound layer. Because of its softness, however, balata is susceptible to cuts or other damage to the cover, and, thus, lacks the durability required to withstand the numerous mis-hits produced by the average golfer.
For this reason, amateur golfers typically prefer a golf ball constructed with a harder, more durable cover material, such as an ionomer or ionomer blend. Covers formed of ionomeric materials generally provide a good combination of distance and durability. Because of the hard ionomer cover, these balls are difficult to cut, but have a very hard xe2x80x9cfeelxe2x80x9d, and a lower spin rate, making these balls more difficult to draw or fade. The differences in the spin rate can be attributed to the differences in the composition and construction of both the cover and the core.
Many attempts have been made to produce a golf ball with the control and feel of a wound balata ball and the durability of a solid, two-piece ionomer-covered ball, but none have succeeded totally. U.S. Pat. Nos. 4,884,814, 5,120,791, 5,324,783 and 5,492,972 are examples of such attempts through blends of high hardness and low hardness ionomers. None of the disclosed ionomer blends, however, have resulted in the ideal balance of carrying distance, coefficient of restitution, spin rate and initial velocity that would approach the highly-desirable playability of a balata covered golf ball. In addition, blends of more than one variety of polymer, e.g., ionomer and balata or ionomer and a non-ionic polymer, have also not successfully been used or have not been disclosed in the prior art for use in golf ball components to achieve a combination of feel and durability.
For example, golf ball components formed of unique blends of ionomers and nonionomers, such as metallocene catalyzed polymers, are absent from the prior art. While blends of ionomers and metallocene catalyzed polymers are not disclosed in the prior art, processes for grafting monomers onto polymers, and, in particular, polyolefins, however, are disclosed in European Patent No. 266994 and U.S. Pat. No. 5,106,916. European Patent No. 266994 discloses a method of admixing a metallocene catalyzed polymer with a monomer capable of bonding to the metallocene catalyzed polymer and an organic peroxide, and mixing the admixture at a temperature greater than the melting point of the metallocene catalyzed polymer for a time sufficient for the post-polymerization reaction to occur. Typically, the mixing is continued for at least four times the half-life of the organic peroxide. Although the monomer, metallocene catalyzed polymer, and the peroxide may be added in any order, preferably, the metallocene catalyzed polymer and monomer are thoroughly mixed before the peroxide is added.
Grafted metallocene catalyzed polymers share the advantages of non-grafted metallocene catalyzed polymers including a narrow molecular weight distribution and uniform molecular architecture. These features provide metallocene catalyzed polymers with properties that are not available with conventional polymers, and allow polymers to be produced having unique properties that are specifically tailored to a particular application. The desired molecular weight distribution and the molecular architecture are obtained by the selection of the appropriate metallocene catalyst and polymerization conditions.
Because the prior art blended compositions lack the combination of durability and distance provided by two-piece golf balls with ionomer covers and the high spin rate and control that is available with three-piece, wound golf balls having balata covers, there remains a need in the art for a golf ball that possesses these characteristics. In particular, there is a need in the art for a golf ball incorporating non-ionomers, such as non-grafted and grafted metallocene catalyzed polymers, and other polymers, such as ionomers and polyamides. The inclusion of foamed and unfoamed grafted metallocene catalyzed polymers and grafted metallocene catalyzed polymer blends will allow highly durable golf balls to be produced with improved performance and virtually any combination of feel and spin rate.
The present invention is directed to a golf ball comprising a layer formed from a composition including at least one polyamide formed from at least one dibasic acid and at least one diamine and at least one metallocene catalyzed polymer, wherein the metallocene catalyzed polymer has been functionalized by sulfonation, carboxylation, addition of an amine or hydroxy, or by grafting an ethylenically unsaturated monomer onto the at least one metallocene catalyzed polymer using a post-polymerization reaction.
The present invention is also directed to a golf ball having a core and a cover, wherein at least a portion of the cover is formed from a composition including a polyamide copolymer formed from at least one dibasic acid and at least one diamine, wherein the at least one dibasic acid comprises about 14 carbons to about 40 carbons, and wherein the polyamide copolymer lacks affinity for water.
The present invention is further directed to a golf ball having a layer formed from a composition including at least one polyamide formed from at least one dibasic acid and at least one diamine and a metallocene catalyzed polymer comprising a copolymer of ethylene or propylene with butene, hexene, or octene.
In one embodiment, the polyamide has a flexural modulus of about 5,000 psi to about 500,000 psi and the metallocene catalyzed polymer has a flexural modulus of about 500 psi to about 200,000 psi. The ethylenically unsaturated monomer may be an olefinic monomer having a functional group selected from the group consisting of sulfonic acid, sulfonic acid derivatives, chlorosulfonic acid, vinyl ethers, vinyl esters, primary amines, secondary amines, tertiary amines, mono-carboxylic acids, dicarboxylic acids, partially or fully ester derivatized mono-carboxylic acids, partially or fully ester derivatized dicarboxylic acids, anhydrides of dicarboxylic acids, cyclic imides of dicarboxylic acids, and ionomeric derivatives thereof. In one embodiment, the ethylenically unsaturated monomer is maleic anhydride.
The composition may further include at least one additional agent selected from the group consisting of coloring agents, reaction enhancers, crosslinking agents, whitening agents, UV absorbers, processing aids, antioxidants, stabilizers, softening agents, plasticizers, impact modifiers, density-adjusting fillers, foaming agents, excipients, reinforcing materials, compatibilizers, and mixtures thereof.
In one embodiment, the layer has a foamed structure.
In another embodiment, the layer has a thickness of about 0.1 inches or less and is disposed between a core and an outer cover. In another embodiment, the layer is an inner cover layer having a thickness of about 0.02 inches to about 0.06 inches. In yet another embodiment, the inner cover layer has a thickness of about 0.02 inches to about 0.35 inches. The outer cover may have a thickness of about 0.02 inches to about 0.035 inches. In one embodiment, the core has a diameter of about 1.5 inches to about 1.6 inches, and in another embodiment, the core includes an inner core layer and an outer core layer.
In one embodiment, the outer cover is formed of a castable reactive liquid material comprising thermoset cast polyurethane, polyurea, epoxy, reaction injection moldable materials, or mixtures thereof. In another embodiment, the layer is a tensioned elastomeric layer.
In another embodiment, the ratio of the Shore D hardness of the outer cover to the layer is about 1.0 or less, the ratio of the thickness of the layer to the outer cover is about 3 or less, or the ratio of the flexural modulus of the layer to the outer cover is about 0.11 to about 4.5. In one embodiment, the polyamide copolymer has a flexural modulus of about 5,000 psi to about 200,000 psi.
In one embodiment, the metallocene catalyzed polymer is functionalized by sulfonation, carboxylation, addition of an amine or hydroxy, or by grafting an ethylenically unsaturated monomer onto the at least one metallocene catalyzed polymer using a post-polymerization reaction. In another embodiment, the composition further includes a non-grafted metallocene catalyzed polymer.
In another embodiment, the composition of the invention further includes an ionomer, wherein the ionomer comprises an E/X/Y copolymer where E comprises ethylene, X comprises a softening comonomer from about 0 weight percent to about 50 weight percent of the copolymer, and Y comprises an xcex1, xcex2-ethylenically unsaturated carboxylic acid from about 5 weight percent to about 35 weight percent of the copolymer, wherein about 1 percent to about 100 percent of the carboxylic acid is neutralized with a metal ion.
In yet another embodiment, the polyamide copolymer is ionomeric and comprises a sulfonated moiety, a carboxylated moiety, or a combination thereof.
Preferred polyamide polymers include polyamide homopolymers, polyamide copolymers and mixtures thereof, where the polyamide polymer has a flexural modulus of about 30,000 psi to about 200,000 psi, where the polyamide homopolymer is polyamide 6, polyamide 11, polyamide 12, polyamide 4,6, polyamide 6,6, polyamide 6,9, polyamide 6,10, polyamide 6,12, 6,18, 6,36, or mixtures thereof, and where the polyamide copolymer is polyamide 6/6,6, polyamide 6,6/6,10, polyamide 6/6,T, polyamide 6/6,6/6,10, polyamide 66,6,18, polyamide 66,6,36, polyamide 6/6,18, polyamide 6/6,36, polyamide 6/6,10/6,18, polyamide 6/6,10/6,36, polyamide 6,10/6,18, polyamide 6,12/6,18, polyamide 6,12/6,36, polyamide 6/66/6,18, polyamide 6/66/6,36, polyamide 66/6,10/6,18, polyamide 66/6,10/6, 36, polyamide 6/6,12/6,18, polyamide 6/6,12/6,36, or mixtures thereof.
The present invention also relates to a golf ball including a cover and a core, where the cover is formed composition that includes a blend of about 1 weight percent to about 99 weight percent of at least one nonionomer polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer. In another embodiment the composition includes a blend of about 0 weight percent to about 99 weight percent of at least one nonionomer polymer and about 100 weight percent to about 1 weight percent of at least one polyamide polymer. In one embodiment, the composition is substantially optical brightener-free.
Nonionomer polymers useful in the invention, when present, have a flexural modulus of about 1,000 psi to about 150,000 psi and include but are not limited to block copoly(ester-ester), block copoly(ester-ether), block copoly(amide-ester), block copoly(amide-ether), block copoly(urethane-ester), block copoly(urethane-ether), a block polystyrene thermoplastic elastomer including an unsaturated rubber, a block polystyrene thermoplastic elastomer including a functionalized substantially saturated rubber, a thermoplastic and elastomer blend including polypropylene and ethylene-propylene-diene monomer terpolymer or ethylene-propylene copolymer rubber where the rubber is dynamically vulcanized, poly(ethylene terephthalate), poly(butylene terephthalate), poly(trimethylene terephthalate), poly(vinyl alcohol), poly(vinyl acetate), poly(silane), poly(vinylidene fluoride), acrylonitrile-butadiene-styrene copolymer, olefinic polymers, their copolymers, including functional comonomers, and mixtures thereof.
In another embodiment, the invention relates to a golf ball including a cover and a core, where the cover is formed of a composition of about 15 weight percent to about 75 weight percent of at least one nonionomer polymer and about 85 weight percent to about 25 weight percent of at least one polyamide polymer. The composition may be substantially optical brightener-free.
An additional embodiment of the present invention is a golf ball including a cover layer, a core layer and at least one intermediate layer interposed between the cover layer and the core layer, where at least one of the layers includes about 1 weight percent to about 99 weight percent of at least one nonionomer thermoplastic polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer. In an additional embodiment, the composition includes about 0 weight percent to about 99 weight percent of at least one nonionomer thermoplastic polymer and about 100 weight percent to about 1 weight percent of at least one polyamide polymer. In yet another embodiment, the composition may be substantially optical brightener-free.
An alternate embodiment of the present invention is directed to a golf ball including a cover layer, a core layer, and at least one intermediate layer interposed between the cover layer and the core layer, wherein at least one of the layers includes a composition having about 1 weight percent to about 99 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer, and where the nonionomer thermoplastic elastomer polymer is selected from the group consisting of block copoly(ester-ester), block copoly(ester-ether), block copoly(amide-ester), block copoly(amide-ether), block copoly(urethane-ester), block copoly(urethane-ether), a thermoplastic and elastomer blend including polypropylene and ethylene-propylene-diene monomer terpolymer or ethylene-propylene copolymer rubber where the rubber is dynamically vulcanized, and mixtures thereof. In yet another embodiment, the composition may be substantially optical brightener-free.
A further alternate embodiment of the present invention is directed to a golf ball including a cover layer, a core layer and at least one intermediate layer interposed between the cover layer and the core layer, where at least one of the layers includes a composition having about 51 weight percent to about 99 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 49 weight percent to about 1 weight percent of at least one polyamide polymer, where the nonionomer thermoplastic elastomer polymer is selected from the group which further includes a block polystyrene thermoplastic elastomer including an unsaturated rubber and a block polystyrene thermoplastic elastomer including a functionalized substantially saturated rubber. The composition may be substantially optical brightener-free.
An additional further alternate embodiment of the present invention is directed to a golf ball including a cover layer, a core layer and at least one intermediate layer interposed between the cover layer and the core layer, where at least one of the layers includes a composition where the nonionomer thermoplastic elastomer polymer is selected from the group which further includes a block polystyrene thermoplastic elastomer including an unsaturated rubber and a block polystyrene thermoplastic elastomer including a functionalized substantially saturated rubber and where the polyamide polymer is combined with an amount of the nonionomer thermoplastic elastomer sufficient to form a mixture such that the flexural modulus of the mixture is less than about 70,000 psi. In one embodiment, the composition is substantially optical brightener-free.
In any of the above additional embodiments and alternate embodiments, when at least one intermediate layer includes polyamide, the cover preferably includes at least one material selected from the group consisting of nonionic olefinic polymers, polyamide, polyolefin ionomers, styrene-butadiene-styrene ionomers, styrene-(hydrogenated butadiene)-styrene ionomers, poly(isoprene), poly(butadiene), a thermoset poly(urethane), and a thermoset poly(urea).
Another embodiment of the present invention is a golf ball including a cover layer, a core layer and at least one intermediate layer interposed between the cover layer and the core layer, where at least one of the layers includes a composition having about 15 weight percent to about 75 weight percent of at least one nonionomer thermoplastic polymer and about 85 weight percent to about 25 weight percent of at least one polyamide polymer. The composition may be substantially optical brightener-free.
Another additional embodiment of the present invention is a golf ball including a cover layer, a core layer and at least one intermediate layer interposed between the cover layer and the core layer, where at least one of the layers includes a composition having about 15 weight percent to about 75 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 85 weight percent to about 25 weight percent of at least one polyamide polymer, and where the nonionomer thermoplastic elastomer polymer is selected from the group consisting of block copoly(ester-ester), block copoly(ester-ether), block copoly(amide-ester), block copoly(amide-ether), block copoly(urethane-ester), block copoly(urethane-ether), a thermoplastic and elastomer blend including polypropylene and ethylene-propylene-diene monomer terpolymer or ethylene-propylene copolymer rubber where the rubber is dynamically vulcanized, and mixtures thereof. In one embodiment, the composition is substantially optical brightener-free.
Another further additional embodiment of the present invention is a golf ball including a cover layer, a core layer and at least one intermediate layer interposed between the cover layer and the core layer, where at least one of the layers includes a composition having about 51 weight percent to about 75 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 49 weight percent to about 25 weight percent of at least one polyamide polymer, where the nonionomer thermoplastic elastomer polymer is selected from the group which further includes a block polystyrene thermoplastic elastomer including an unsaturated rubber and a block polystyrene thermoplastic elastomer including a functionalized substantially saturated rubber. In one embodiment, the composition is substantially optical brightener-free.
In a separate embodiment of the present invention, a golf ball including a cover layer and a core has at least one intermediate layer interposed between the cover layer and the core, where one of the layers includes a composition having about 1 weight percent to about 99 weight percent of at least one nonionomer thermoplastic polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer, and where another layer includes a thermoset polymer. Alternatively, however, in a further separate embodiment the composition includes about 0 weight percent to about 99 weight percent of at least one nonionomer thermoplastic polymer and about 100 weight percent to about 1 weight percent of at least one polyamide polymer. The composition may be substantially optical brightener-free.
In a further separate embodiment of the present invention, a golf ball including a cover layer and a core has at least one intermediate layer interposed between the cover layer and the core, where one of the layers includes a composition having about 1 weight percent to about 99 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer, where the nonionomer thermoplastic elastomer polymer is selected from the group consisting of block copoly(ester-ester), block copoly(ester-ether), block copoly(amide-ester), block copoly(amide-ether), block copoly(urethane-ester), block copoly(urethane-ether), a thermoplastic and elastomer blend including polypropylene and ethylene-propylene-diene monomer terpolymer or ethylene-propylene copolymer rubber where the rubber is dynamically vulcanized, and mixtures thereof, and where an other one of the layers includes a thermoset polymer. The composition may be substantially optical brightener-free.
In an additional further separate embodiment of the present invention, a golf ball including a cover layer and a core has at least one intermediate layer interposed between the cover layer and the core, where one of the layers includes a composition having about 51 weight percent to about 99 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 49 weight percent to about 1 weight percent of at least one polyamide polymer, where the nonionomer thermoplastic elastomer polymer is selected from the group which further includes a block polystyrene thermoplastic elastomer including an unsaturated rubber and a block polystyrene thermoplastic elastomer including a functionalized substantially saturated rubber. In one embodiment, the composition is substantially optical brightener-free.
Thermoset polymers useful in the invention include but are not limited to poly(isoprene), poly(butadiene), poly(urethane), poly(urea), epoxy, silicone, and mixtures thereof.
The invention also relates to a method of making a golf ball, which includes forming a golf ball core, preparing a composition of about 1 weight percent to about 99 weight percent of at least one nonionomer polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer, and molding the blend around the golf ball core to form the golf ball. Alternatively, however, the composition includes about 0 weight percent to about 99 weight percent of at least one nonionomer polymer and about 100 weight percent to about 1 weight percent of at least one polyamide polymer. The composition may be substantially optical brightener-free.
The invention also further relates to a method of making a golf ball, which includes forming a core layer, forming at least one intermediate layer about the core layer, and forming a cover layer over the at least one intermediate layer, where at least one of the layers is formed of a composition including about 1 weight percent to about 99 weight percent of at least one nonionomer thermoplastic polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer. Alternatively, however, the composition includes about 0 weight percent to about 99 weight percent of at least one nonionomer thermoplastic polymer and about 100 weight percent to about 1 weight percent of at least one polyamide polymer. The composition may be substantially optical brightener-free.
The invention also additionally relates to a method of making a golf ball, which includes forming a core layer, forming at least one intermediate layer about the core layer, and forming a cover layer over the at least one intermediate layer, where at least one of the layers is formed of a composition including about 1 weight percent to about 99 weight percent of at least one nonionomer thermoplastic elastomer polymer and about 99 weight percent to about 1 weight percent of at least one polyamide polymer, and where the nonionomer thermoplastic elastomer polymer is selected from the group consisting of block copoly(ester-ester), block copoly(ester-ether), block copoly(amide-ester), block copoly(amide-ether), block copoly(urethane-ester), block copoly(urethane-ether), a thermoplastic and elastomer blend including polypropylene and ethylene-propylene-diene monomer terpolymer or ethylene-propylene copolymer rubber where the rubber is dynamically vulcanized, and mixtures thereof. In one embodiment, the composition is substantially optical brightener-free.
The present invention is also directed to golf balls having at least one foamed or unfoamed layer in at least one of the cover, the core, or in one or more intermediate mantles between the cover and the core, where the layer is formed from a composition including at least one metallocene catalyzed polymer that has been functionalized by sulfonation, carboxylation, addition of an amine or hydroxy, or by grafting an ethylenically unsaturated monomer onto the at least one metallocene catalyzed polymer using a post-polymerization reaction. The ethylenically unsaturated monomer is typically an olefinic monomer having a functional group selected from the group consisting of sulfonic acid, sulfonic acid derivatives, chlorosulfonic acid, vinyl ethers, vinyl esters, primary amines, secondary amines, tertiary amines, mono-carboxylic acids, dicarboxylic acids, partially or fully ester derivatized mono-carboxylic acids, partially or fully ester derivatized dicarboxylic acids, anhydrides of dicarboxylic acids, cyclic imides of dicarboxylic acids and ionomeric derivatives thereof. Preferably, the ethylenically unsaturated monomer is maleic anhydride.
The golf ball compositions of the invention may include a blend of at least one grafted metallocene catalyzed polymer and at least one of an ionomer, a non-grafted, i.e., unfunctionalized, metallocene catalyzed polymer, or a non-ionomeric polymer. Preferably, the composition is a blend of at least one grafted metallocene catalyzed polymer and at least one ionomer, and includes about 5 parts per hundred (phr) to about 90 phr of at least one grafted metallocene catalyzed polymer and about 95 phr to about 10 phr of at least one ionomer, more preferably about 10 phr to about 75 phr of at least one grafted metallocene catalyzed polymer and about 90 phr to about 25 phr of at least one ionomer, and most preferably about 10 phr to about 50 phr of at least one grafted metallocene catalyzed polymer and about 90 phr to about 50 phr of at least one ionomer. Typically, the layer has a Shore D hardness of about 15 to about 80 and a thickness of about 0.005 inch to about 0.125 inch, and the core has a diameter of about 1.0 inch to about 1.63 inches. In addition, a typical grafted metallocene catalyzed polymer has a flexural modulus of about 500 psi to about 200,000 psi, preferably about 1,000 psi to about 150,000 psi and the ionomer has a flexural modulus of about 50 psi to about 150,000 psi. Any of the cover, the core, or a mantle between the cover and the core may further include a density increasing filler material.
Preferably, the grafted metallocene catalyzed polymer is formed by grafting an ethylenically unsaturated monomer onto a metallocene catalyzed polymer selected from the group consisting of polyethylene and copolymers of ethylene with propylene, butene, pentene, hexene, heptene, octene, and norbomene, most preferably, copolymers of ethylene with butene, pentene, hexene, heptene, octene, and norbornene, but may be formed by grafting an ethylenically unsaturated monomer onto any metallocene catalyzed polymer of the formula: 
wherein
R1 is hydrogen;
R2 is hydrogen or lower alkyl selected from the group consisting of CH3, C2H5, C3H7, C4H9, and C5H11;
R3 is hydrogen or lower alkyl selected from the group consisting of CH3, C2H5, C3H7, C4H9, and C5H11;
R4 is selected from the group consisting of H, CH3, C2H5, C3H7, C4H9, C5H11, C6H13, C7H15, C8H17, C9H19, C10H21, and phenyl, in which from 0 to 5 H within R4 can be replaced by substituents selected from the group consisting of COOH, SO3H, NH2, F, Cl, Br, I, OH, SH, silicone, lower alkyl esters and lower alkyl ethers, with the proviso that R3 and R4 can be combined to form a bicyclic ring;
R5 is hydrogen, lower alkyl including C1-C5, carbocyclic, aromatic or heterocyclic;
R6 is hydrogen, lower alkyl including C1-C5, carbocyclic, aromatic or heterocyclic; and wherein x is about 99 weight percent to about 50 weight percent of the polymer, y is about 1 to about 50 weight percent of the polymer and z is about 0 to 49 weight percent of the polymer.